NOTES ON SOME PARASITIC PROTISTS. 11333; 
their relation with the Bacteria. I prefer, therefore, to 
employ the non-committal name of “ protist.” 
APPENDIX. 
On the Methods Employed in the Examination of 
Bacteria and Allied Organisms. 
The methods usually employed by the bacteriologist for 
purposes of medical diagnosis are far too crude for the 
cytologist. It is not likely that a dried, plasmolysed, and 
flame-fixed mummy of a microbe can furnish much informa- 
tion regarding its structure during life. And, again, too 
much weight should not be given to observations made upon 
organisms grown in artificial and abnormal culture media. 
Such media are of the greatest value in the hands of the 
breeder of pathogenic Bacteria, but the development of the 
organisms in them cannot be unreservedly accepted as their 
normal life-history. The protistologist who would investigate 
the real ways of life of Bacteria must study them in their 
native medium, in the living state, and in carefully fixed and 
stained preparations. 
-Endoparasitic Bacteria usually survive but a short time in 
hanging drop preparations. They are much more suitably 
treated by being rapidly placed on a slide, covered with a 
coverslip with wax feet, and rapidly waxed round the edge 
with a small candle. In such preparations, if quickly and 
carefully made, they will live for a long time. They are 
best examined by means of a water-immersion apochromatic 
objective. 
Intravitam staining is often very serviceable. The stains 
which have generally proved most useful are methylene blue, 
neutral red, and Brillantkresylblau. | 
All of these stains impart a more or less red colour to the 
metachromic granules during life. 
In order to make good permanent preparations it is often 
necessary to dilute the medium in which the bacteria live. 
